fortify.

To give power, strength, or vigour to (oneself or someone, or to something); to strengthen.

To support (one's or someone's opinion, statement, etc.) by producing evidence, etc.; to confirm, to corroborate.

To increase the nutritional value of (food) by adding ingredients, especially minerals or vitamins.

Soy milk is often fortified with calcium.

To impart fortitude or moral strength to (someone or their determination, or something); to encourage.

To make (something) defensible against attack by hostile forces.

To make (something) structurally strong; to strengthen.

To increase the defences of (an army, soldiers, etc.), or put (it or them) in a defensive position.

To secure and strengthen (a place, its walls, etc.) by installing fortifications or other military works.

To provide (a city, a fortress, an army, etc.) with equipment or soldiers.

To add spirits to (wine) to increase the alcohol content.

Sherry is made by fortifying wine.

To install fortifications or other military works; also (sometimes figurative), to put up a defensive position.

To become strong; to strengthen.

To undergo, or cause to undergo, fortition.